Running a filament lamp on overvoltage will decrease its life, disproportionately, (exponentially? ).
So a 24 volt lamp on 30 volts will have a considerably shorter life especially as the initial No Load voltage may well be higher. If you could run the 24 volt lamp in series with something that drops 6 volts when taking the same current as the 24 volt bulb, you would be home and dry. (If you could find one, a 6 volt lamp of the same wattage, or maybe a 12 volt of double the wattage, as the 24 volt worklight?). A resistor dropping 6 volts at the current consumption of the main lamp is likely to become quite hot. Useful as additional heating in the winter, but not so good in the summer!
Hhad the supply been Dc, it might have been possible to find a couple of solid state 12 volt regulators, capable of withstanding the current draw, and connected in series with each other (on a suitable heatsink ), and the 24 volt lamp.
Just a few thoughts
Howard
An extreme case was that of Photoflood bulbs, BRIGHT but shortlived. They were actually 110 volt, but run on 230/240 volts had a life of a very few hours. The current surge on start up was what did the damage. Soft starting on a lower voltage to heat the filament extended life considerably.
Howard